Gerardo, it looks like you have been using AC for a long time.
Some time ago, I was trying to do the same thing. I had figured out a way but had forgotten. Your posting made me go back and figure out what I had done.
Under schedule/months since last seen put in a high number (I tried 199) this should give you all those never seen. Unfortunately, some will be those referred 10 years ago. But this should create your list.
